Tower furnace and feed

ABSTRACT

Means to supply clay particles to fall through a tower furnace comprising a rotating drum having particle-receiving indentations on its surface. As the drum is rotated, particles are picked up by it and dropped vertically in a substantially constant stream into and through the furnace.

United States Patent 222/368 X 222/345 X 214/35 214/35 222/349 X 222/368 X 222/368 X 266/27 X 222/345 X inventors Ernst A. Siemssen 1,402,184 1/1922 Sinclair Gwynedd; 1,519,928 12/1924 Priesnitz John M. Hummel, Doylestown, both of, Pa. 1,618,01 1 2/1927 lsenberg et al. Appl. No. 832,197 2,113,015 4/1938 Daniels Filed June 11, 1969 2,278,948 4/1942 Rodli et a1. Patented Aug. 24, 1971 2,907,444 10/1959 Smith Assignee Selas Corporation of America 3,072,301 1/1963 Burke 3,131,821 5/1964 Tsujihata et a1. 2,906,438 9/1959 Carpenter TOWER FURNACE AND FEED FOREiGN PATENTS 5 D'Wmg 934,073 8/1963 Great Britain 11.8. C1 222652212 Primary Examiner lames M Meme, 1m. cu 1 27b 1/20 wenfmd Field 01 Search .1 266/27;

214/35; 222/345, 349, 368, 414, 410 ABSTRACT: Means to supply clay particles to fall through a tower furnace comprising a rotating drum having particle- References cued receiving indentations on its surface. As the drum is rotated, UNITED STATES PATENTS particles are picked up by it and dropped vertically in a sub- 1,307,349 6/1919 Draver 222/368 stantially constant stream into and through the furnace.

PATENTEI] AUG24|97| FIG. 3

FIG.

FIG.4

INVENTOK SIEMSSEN HUMMEL TOWER FURNACE ANlD FEED BACKGROUND AND SUMMARY The present invention relates to tower furnaces, and is more particularly directed to the combination of such a furnace and a feed mechanism for supplying particles to be bloated to such a furnace.

In the manufacture of lightweight aggregate or ceramic foam, dried clay particles are dropped through a tower furnace where they are fused and bloated before collection individually, as aggregate, or in slab form for use .as ceramic foam. In order to obtain the desired product it is necessary to drop the particles in such a fashion that they fall and bloat individually before they are collected. Various means have been devised for this purpose for dropping relatively small quantities of particles. For larger quantities a different piece ofapparatus is required. Regardless of the quantity being dropped,

however, they should bedropped so that they fall freely in a substantially steady steam through the furnace.

It is an object of the invention to provide a particle feed means for use in a tower furnace. It is a further object of the invention to provide apparatus for dropping particles of .clay or similar material in a substantially steady stream from a point of supply into a particular location in a tower furnace.

In practicing the invention there is provided a supply of particles, usually clay with a small amount of abloating agent, that is moved over a fluidized bed to remove dust and, if desired, to preheat them. The particles are then directed through a chute to the surface of a horizontally rotating feed roll having indentations on its surface. As the roll rotates it moves the particles to the desired location above the furnace and drops them into the furnace where they are fused.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which we have illustrated and described a preferred embodiment of the invention. 1

IN THE DRAWINGS FIG. 1 is a view, partly in section, through the furnace and the mechanism for feeding material to the furnace.

FIG. 2 is a view taken on line 2--2 of FIG. 1.

FIG. 3 is a view taken on line.33 ofFlG. 2, and

FIGS. 4 and- 5 show feed rollers with different types of indentations.

DETAILED DESCRIPTION Referring to the drawings, there is shown a supply hopper l in which particles to be bloated are placed. These particles flow across a fluidized bed 2 to a chute 3 and a feed mechanism indicated generally at 4. This feed mechanism drops the particles into a tower furnace 5 which is shown somewhat diagrammatically. A furnace of this type includes an unobstructed, vertically extending, furnace chamber 6 that is fired by a plurality of rows of burners 7 which supply the heat necessary to fuse and bloat the particles. The particles are collected in a manner explained in US. Pat. No. 3,056,] 84 on a belt 8 by which they are moved from the furnace through a suitable annealing apparatus. Usually, there is provided a parting agent on the belt upon which the bloated particles are collected. This parting agent is supplied from a hopper 9. It is noted that the fluidized bed serves in the usual fashion of apparatUs of this type, to float the particles across its surface and, in so doing, the dust from the particles is removed so that it will not cloud the furnace chamber. Fluidizing air, which may be heated to preheat the particles, is supplied through an inlet 11 and the exhaust air is removed through an outlet 12.

' The feed mechanism 4 with which the invention is particularly concerned is located in a housing 13 fixed to the top of the furnace. Chute 3 forms the inlet of the housing, while the outlet is formed by a portion 14 extending vertically downward over the center of the furnace. Particles are fed in a regulated manner from the inlet to the outlet by a hollow feed roller 15 that is provided with hollow shafts 16 journaled in bearings 17 formed as a part of or attached to housing 13. Outlet 14 extends at a tangent to the surface of the feed roller. The feed roller is driven in a clockwise direction in FIG. 3 by a motor 18. Cooling air is forced through roller 15 by way of shafts l6.

Feed roller 15 is provided on its surface with a plurality of indentations which receive the particles from inlet 3 and transfer them to outlet 14. The roller of FIGS. 2 and 3 is shown as having indentations in the form of axially extending grooves 19 on the surface. Particles descending from fluidized particles received by each groove 19 being regulated by a doctor blade 22. It will be noted that the angle of repose of the particles below baffle 21, shown at 23, is to the right of a vertical plane through the axis'of roller 15. If any small amount of particles should fall to the left of the roller, they will go into a cleanout opening 24.

The object of feed roller 15 is to deliver a constant and uniform supply of particles vertically downward in a thin sheet to the furnace. The width of this sheet or the axial extent of roller 15 that is used can be varied by members 25 that can be moved inwardly from the sides of housing 13 along the lower edge of baffle2l. Also, if desired, a movable shield can be used between the housing 13 and the furnace in order to prevent heating of the feed mechanism while the furnace is being heated up prior to the beginning of the feed of the particles.

The indentations on the surface of feed roller 15 can take several forms. The indentations in FIGS. 2 and 3 are shown as being grooves 19 extending in an axial .directionon the surface of the roller. In FIG. 4 the grooves 26 are shown as extending helically along the surface of the roller. In FIG. 5 the indentations are shown as being a series of cup-shaped depressions 27 formed on the surface of the drums.

With any of the forms of the invention, particles are delivered in a substantially constant supply, generally in the form ofa sheet, which permits heat to be absorbed individually by the particles so that the bloating thereof will be uniform. Because of the manner in which the particles are dropped, a slabformed therefrom will have substantially uniform thickness from side to side. The thickness of such a slab for a given roller length will, of course, depend jointly upon the speed of rotation of roller 15 and the speed of collecting belt 8.

While in accordance with the provisions of the Statutes we have illustrated and described the best form of embodiment of our invention now known to us, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention set forth in the appended claims, and that in some cases certain features of our invention may be used to advantage without a corresponding use of other features.

What we claim is:

1. In a tower furnace system, means to supply particles to be heated, a tower furnace having an unobstructed chamber through which particles are dropped in a free fall, and means between said supply means and said furnace to control the feed of particles into said furnace comprising an outlet portion above and extending directly into said furnace chamber, a feed roller mounted above and with its periphery tangent to inlet portion extending from said supply means to above said roller, said roller being formed with particle receiving indentations on its surface, and means to rotate said roller whereby particles placed on its surface by said inlet portion will be delivered through said outlet portion directly to said furnace chamber.

2. The combination of claim 1 in which said indentations are grooves extending axially along the surface of said roller.

3. The combination of claim 1 in which said indentations are grooves extending helically along the axis ofsaid roller.

4. The combination of claim 1 in which said. indentations are cup-shaped depressions on the surface ofsaid feed roller.

5. In a tower furnace system, means to supply particles to be heated, a tower furnace through which particles are dropped, and means between said supply means and said furnace to UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,601,380 Dated AUGUST 24, 1971 Inventor(s) ERNST A, SIEMSSEN and JOHN M. HUT [MEL It is certified that error a ppears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2 between lines 72 and 73, insert--and out of contact with said outlet portion, an-- Signed and sealed this 27th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents )RM PO-1 050 (10-69] USCOMM-DC 60375-P69 s u s sovzmmznr PRINTING OFFICE I969 0-3554 

1. In a tower furnace system, means to supply particles to be heated, a tower furnace having an unobstructed chamber through which particles are dropped in a free fall, and means between said supply means and said furnace to control the feed of particles into said furnace comprising an outlet portion above and extending directly into said furnace chamber, a feed roller mounted above and with its periphery tangent to inlet portion extending from said supply means to above said roller, said roller being formed with particle receiving indentations on its surface, and means to rotate said roller whereby particles placed on its surface by said inlet portion will be delivered through said outlet portion directly to said furnace chamber.
 2. The combination of claim 1 in which said indentations are grooves extending axially along the surface of said roller.
 3. The combination of claim 1 in which said indentations are grooves extending helically along the axis of said roller.
 4. The combination of claim 1 in which said indentations are cup-shaped depressions on the surface of said feed roller.
 5. In a tower furnace system, means to supply particles to be heated, a tower furnace through which particles are dropped, and means between said supply means and said furnace to control the feed of particles into said furnace comprising an outlet portion above and extending into said furnace, a feed roller mounted above and with its periphery tangent to said outlet portion, an inlet portion extending from said supply means to above said roller, said roller being formed with particle receiving indentations on its surface, and means to rotate said roller whereby particles placed on its surface by said inlet portion will be delivered through said outlet portion to said furnace, said supply means including a fluidized bed, said inlet portion forming the discharge from said fluidized bed. 